In the gear manufacturing sector, a known method of making gears consists of machining a set of teeth on a corresponding piece and subsequently grinding the toothed piece. Each gear cutting and grinding process comprises a respective rough machining phase and a finishing phase of the piece.
Generally, the gear cutting or grinding process is performed by a working machine that comprises a piece-holder table mounted so as to rotate about its own longitudinal vertical axis and an operating head, which is provided with at least one tool for machining the piece, and is movable along a guiding device that extends in a direction substantially transversal to the longitudinal axis of the piece-holder table.
Different tools can be used to perform the rough machining and finishing processes in order to increase machine productivity. It is thus possible to optimize each machining process and cut cycle times. In general, more and more often to perform a complete gear cutting process it is becoming necessary to equip a single tool-carrier with several tools that can perform different machining processes in a single position. Normally the number of tools that can be used and their width is limited by the length of the stroke of the operating head.
Nowadays, the need has arisen to produce gears with particularly large nominal diameters for use in special applications, such as, for instance, in the production of wind power generators.